Abstract

Sandstones of the Pyeongan Supergroup vary from quartzose to quartzo-feldspathic in composition. The introduction of significant amounts of plagioclase and K-feldspar in upper formations of the Pyeongan Supergroup may be related to a change in tectonic stability of the source area from a relatively stable cratonic interior to an uplifted basement. The absence of sandstones rich in lithic fragments in the Korean Peninsula, including the Pyeongan and Daedong supergroups, the latter of which is supposedly post-collision between the North and South China blocks, suggests that a recycled orogen had never been emplaced in Korea. Reference of the tectonic divisions of Korea to those of China or Japan should be made with substantial care. This includes the current attempts to relate the Imjingang Belt with the Qinling-Dabieshan Belt, or the Ogcheon Belt with the Hida Belt.